Collaborative Research: Characterizing Sources and Sinks of the Oxidative Potential of Indoor Particulate Matter

在今天的现代世界，人们大约90%的时间是在室内环境中度过的，包括住宅、办公室/学校以及商业、娱乐和娱乐设施。在室内环境中，人们可能接触到各种空气污染物，包括通常被称为PM2.5的细颗粒物，PM2.5被定义为直径(≤)小于或等于2.5微米的细颗粒物。像PM2.5这样的细颗粒物可以穿透人类的肺部，通过产生活性氧物种(ROS)对肺部生物组织造成损害。PM2.5产生ROS的能力，也被称为氧化势(OP)，已经成为一种潜在的新指标，可能比仅仅反映其质量浓度更能反映其对健康的影响。然而，到目前为止，关于室内细颗粒物来源的OP的研究非常有限。为了解决这一知识差距，该项目的首席调查员建议全面调查和表征室内PM2.5的源/汇，目的是促进对来自室内和室外的室内PM2.5的OP和反应性的基本了解。这一项目的成功完成将使社会受益，因为它将通过制定和实施一个框架来研究和验证有机污染物作为衡量室内PM2.5在包括住宅和商业建筑在内的建成环境中对健康影响的新指标。通过学生教育和培训将为社会带来更多好处，包括指导伊利诺伊大学厄巴纳-香槟分校的一名研究生和伊利诺伊理工学院的一名研究生。暴露在可吸入细颗粒物(PM2.5)中会增加发病率和死亡率。然而，与室外浓度相比，个人暴露于PM2.5的浓度与室内浓度的相关性要强得多，因为人们大部分时间都呆在室内，室内和室外都存在污染物。此外，这些关联的原因机制仍然不清楚，基于质量的PM2.5浓度测量不能提供关于PM2.5固有毒性的信息。氧化势(OP)，即PM2.5产生氧化剂的能力，是一种很有前途的空气污染健康指标，在流行病学研究中受到越来越多的关注。该项目的主要目标是从机理上理解室内PM2.5的运算性和反应性，这是由室内和环境来源造成的。这项研究的具体目标是：1)通过开发新的方法/测试来测量源和汇过程，调查室内和环境源中PM2.5的OP和反应性的演变和动态；2)建立各种室内源排放的PM2.5 OP的清单；以及3)对在具有代表性的室内环境中测量PM2.5 OP的源和汇(反应性损失)的方法/测试进行现场评估和验证。这项研究的成功完成有可能通过产生关于室内PM2.5排放(源和汇)及其运行和反应性的新数据和基础知识来产生变革的影响。为了实现该项目的教育和培训目标，首席调查员建议利用伊利诺伊大学香槟分校(UIUC)和伊利诺伊理工学院(IIT)的现有计划来设计和实施夏令营，以培训高中生进行环境空气质量监测方面的培训，包括使用低成本室内空气采样器。此外，PIS计划将研究成果整合到UIUC和IIT现有的空气质量本科生/研究生课程中，以提高未来环境工程工作者对室内空气质量的重要性以及为保护公众健康而测量和控制室内空气质量所需工具/技术的认识。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In today’s modern world, people spend about 90% of their time in indoor environments including residential homes, offices/schools, and commercial, entertainment, and recreational facilities. In indoor environments, people can be exposed to various air pollutants including fine particles commonly referred to as PM2.5 , which is defined as fine particulate matter with diameter less/equal (≤) than 2.5 microns. Fine particles such PM2.5 can penetrate the human lungs and cause damage to lung biological tissues by generating reactive oxygen species (ROS). The ability of PM2.5 to generate ROS, also called its oxidative potential (OP), has emerged as a potential new metric that may better capture their health effects than their mass concentration alone. However, there are very limited studies of the OP of indoor sources of fine particles to date. To address this knowledge gap, the Principal Investigators (PIs) of this project propose to comprehensively investigate and characterize the sources/sinks of indoor PM2.5 with the goal of advancing the fundamental understanding of the OP and reactivity of indoor PM2.5 coming from both indoor and outdoor sources. The successful completion of this project will benefit society through the development and implementation of a framework for studying and validating the OP as a new measure of the health impact of indoor PM2.5 in the built environment including residential and commercial buildings. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student at the University of Illinois Urbana-Champaign and one graduate student at the Illinois Institute of Technology.Exposure to inhalable fine particulate matter (PM2.5) can lead to increased incidence of disease and mortality. However, personal exposure to PM2.5 is much more strongly correlated with indoor concentrations than outdoor concentrations because people spend most of their time indoors where pollutants of both indoor and outdoor origin are present. In addition, the causal mechanisms of these associations are still unclear, and mass-based measurements of PM2.5 concentrations do not provide information on the inherent toxicity of PM2.5. The oxidative potential (OP), defined as the capability of PM2.5 to generate oxidants, is a promising health metric of air pollution that is receiving increasing attention in epidemiological studies. The overarching goal of this project is to develop a mechanistic understanding of the OP and reactivity of indoor PM2.5 resulting from both indoor and ambient sources. The specific objectives of the research are to 1) investigate the evolution and dynamics of the OP and reactivity of indoor PM2.5 from indoor and ambient sources by developing new methods/assays to measure source and sink processes; 2) establish an inventory of the OP of PM2.5 emitted from various indoor sources; and 3) conduct field-evaluation and validation of the methods/assays to measure the sources and sinks (loss of reactivity) of PM2.5 OP in a representative indoor environment. The successful completion of this research has the potential for transformative impact through the generation of new data and fundamental knowledge on the emissions (sources and sinks) of indoor PM2.5 and their OP and reactivity. To implement the education and training goals of this project, the Principal Investigators (PIs) propose to leverage existing programs at the University of Illinois Urbana-Champaign (UIUC) and the Illinois Institute of Technology (IIT) to design and implement a summer camp to train high school students in environmental air quality monitoring including the use of low-cost indoor air samplers. In addition, the PIs plan to integrate the research findings into existing undergraduate/graduate courses on air quality at UIUC and IIT to increase the awareness of the future environmental engineering workforce of the importance of indoor air quality and the required tools/technologies to measure and control it for the protection of public health.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.